gavinandresen/bitcoin-git — comment on commit 440710c57df1c27f66cf828ce7746694db070709
File: src/main.cpp line 1655
By gavinandresen:

why push-4-bytes for the height: I ran a tool that looked at previous coinbases, and no-opcode turned up plausible heights, as did the push-3-bytes-opcode. push-4 was completely clean for all existing coinbases.